Working with nature to control weeds

Over 40 people attended a Biological Weed Control Seminar in Crookwell last week and a further 25 in Gunning with Biological Weed control specialist, Barry Sampson , Australia’s only commercial weed biological control specialist.

The day was part of the Tussock Tamers Integrated Weed Management Program to showcase what biological agents are out there and available and how they can be used as part of an integrated weed management plan.

Participants learnt that there are Biological agents, including weevils, moths, mites, beetles and rusts, available for problematic weeds, such as St John’s wort, horehound, Paterson’s curse, bridal creeper, thistle, dock, prickly pear, blackberry, heliotrope and thorn apple. The larvae and adults feed on the crown, leaves and roots, leading to the death of the plant or reducing seed production. They also learned that many of them are already out there working in our district.

Mr Sampson said the majority of farmers, land occupiers and government bodies wanted to reduce their chemical use on weeds. He said the key to sustainable weed management was an integrated program using biological, mechanical and chemical control. The concept of Weed Biological Control is to reduce seed banks therefore it is to be viewed as a long term measure as many weeds have a huge seed bank. The density and vigor of plants can be reduced over time and the measure of success is to have a good integrated management program. In the higher rainfall zones, farmers with St John’s wort infestations have access to a mite with the capacity to reduce plant density and vigour by up to 60 per cent.

Mr Sampson said that the aim of biological control is to try to reduce the cost of control of weeds so they can be more manageable in the long term. As we all are aware many weeds are a huge problem and if they can be reduced the problem is more manageable. They are never going to wipe out the problem on their own but they can reduce the density and vigour to make the weeds more manageable. He said bio agents were ideal in hilly terrain where other control methods were expensive or unsafe.

It was great to have all of the Upper Lachlan Shire Council’s Weed officers at the seminars with a wealth of local knowledge about bio control programs that the council has been involved in and the extent of certain weed infestations etc.

As with all Landcare events the catering was first class, with many thanks and praise to the Upper Lachlan Chair person Nerida Croker and Rosemary Spiller for a wonderful job organising and catering the two events.

If you are considering releasing some biocontrol agents it is a good idea to get in touch with your local landcare group to find out if anyone else is doing the same thing. (contact me if you do not have details of your local group mary@upperlachlanlandcare.org.au) This could save money be more effective.

NB Fullerton/Hadley have plans to have a further biological weed control day in the near future as do Hovell’s Creek.

Ray Shiel and Trevor Brogan at Gunning Seminar

Gunning Weeds Officer Rob Gorman, Chris Fowler and Det Voges

8 year old Keeara Westin from Yass Landcare enjoyed watching some of the biocontrol agents in action

Barry Sampson looking for signs of bio activity in Crookwell

Evidence of root weevils in the Patterson’s curse in Crookwell

Looking for signs of biological agents in Crookwell with Weeds Officer Geoff Nicholson